release: publish RustQueue 0.8.0

[SamuelSupe]

Summary

• add a Kodo-compatible producer Gateway so Kodo can keep using Discovery while publishing through stable Proxy identities
• expose standard NSQ /stats fields with durable monotonic topic/channel counters
• fail closed for unauthenticated Kodo channel cleanup and add authenticated native management/token rotation paths
• raise the validated wire/storage limit to 100 MiB and support Kodo's exact 104,857,500-byte maximum
• harden Gateway retry semantics, drain/disk-pressure routing, rolling cutover, operator preflight, and HA status handling
• bump workspace, Helm chart, images, docs, fixtures, and release metadata to 0.8.0

Why

Kodo directly consumes Discovery /nodes, parses the standard NSQ stats schema, and attempts unauthenticated channel cleanup. RustQueue's producer routing, stats shape, administrative authentication, and former message-size limit did not satisfy those assumptions. This release adds the compatibility boundary inside RustQueue, without requiring upstream Kodo changes.

Operational impact

• Kodo /nodes receives three stable Gateway identities; consumer /lookup continues to return Brokers.
• Broker retry only occurs before a publish can have committed; ambiguous post-write outcomes are not replayed.
• Kodo cleanup remains disabled/fail-closed unless the authenticated native management flow is configured.
• Existing clusters must complete the documented rolling upgrade/readiness fence before producers send payloads above their old limit.

Validation

• FULL=1 K8S_ACCEPTANCE=0 KODO_ACCEPTANCE=1 KODO_SOURCE_DIR=../kodo-master FUZZ_SECONDS=1 ./scripts/release-gate.sh
• Rust fmt, locked all-feature check/test, Clippy, console typecheck/build, Helm lint/template
• all seven fuzz targets
• Go and Python NSQ compatibility in plain and secure modes
• real Kodo source response replay
• exact 104,857,500-byte PUB/DPUB with one Gateway failover
• three-Broker acceptance: 3,239 expected and unique, 0 missing, 0 duplicates, 0 publish errors